Eye movements in health and disease

Question 1

CN3

Answer 1

MR IR SR IO

Question 2

MR

Answer 2

Adduct eye

Question 3

SR

Answer 3

Abduct and up

Question 4

IO

Answer 4

Adduct and down

Question 5

IR

Answer 5

ABduct and down

Question 6

CN4

Answer 6

SO

Question 7

SO

Answer 7

Adduct and down

Question 8

Cn6

Answer 8

LR

Question 9

LR

Answer 9

Abduct eye

Question 10

Difference between recti muscles and obliques

Answer 10

Recti muscles pull towards themselves and oblique pulls away

Question 11

Levator palpabele superioris innervation and function

Answer 11

Oculomotor, eye lid elevation

Question 12

Ciliary muscle innervation and function

Answer 12

Oculomotor, changes lens shape for accommodation

Question 13

Pupillary sphincter innervation and function

Answer 13

Oculomotor, constricts pupil

Question 14

Pupil dilator muscle innervation and function

Answer 14

Trigeminal, dilates pupil

Question 15

What is convergence?

Answer 15

Both eyes point medially to see near objects

Question 16

What is conjugation?

Answer 16

Eyes must move together

Question 17

What is accommodation?

Answer 17

Lens shaped to focus light coming from viewed object

Question 18

Myopia

Answer 18

Short sighted

Light rays converge before retina - can’t see far away objects

Question 19

Hypermetropia

Answer 19

Long sighted

Light rays converge behind retina

Question 20

Saccades movements

Answer 20

Rapid, jerky movements of the eye

Question 21

Where are the nuclei of the 3,4 and 6 CN?

Answer 21

3 and 4 in brainstem, 6 in pons

Question 22

CN3 palsy

Answer 22

Down and out

Question 23

CN4 palsy

Answer 23

Head tilt

Question 24

CN6 palsy

Answer 24

ADDUCTION

Question 25

PITS

Answer 25

Lesion in parietal lobe = inferior quadrantopia

Lesion in temporal lobe = superior quadrantopia

Question 26

Temple and nasal sides

Answer 26

Temple side carries vision friom nasal side and vice versa

Nasal side crosses after optic chiasm

Question 27

Central scotoma

Answer 27

The macula is in the centre of the retina and is most concentrated with cells - damage to macula causes central scotoma

Question 28

Central sparing

Answer 28

Posterior cerebral artery

Question 29

Symptoms of cerebellar lesions

Answer 29

DANISH - like a drunk

Question 30

Double vision when looking to right

Answer 30

Right abducens

Question 31

Causes of cranial nerve palsies

Answer 31

• Ischemia (strokes)
• Compression (tumour, abscess, aneurysm)
• Trauma (concussion, whiplash)
• Microvascular disease (diabetes)
• Migraines (e.g. ophthalmoplegic migraines)
• Raised ICP
• Congenital

Question 32

Nystagmus

Answer 32

Rapid, jerky movements of the eye, can be horizontal or vertical and cause beating at the extremes

Question 33

Labyrinthitis

Answer 33

• Inflammation of inner ear
• Normally due to viral infection
• Nystagmus, vertigo, hearing loss/tinnitus and virus symptoms
• 2+ months to recover
• No specific treatment unless bacterial/other cause
• Strokes don’t affect young and don’t cause viral infections

Question 34

Neuromyelitis optica

Answer 34

• Caused by anti-aquaporin 4 antibodies
• Optic neuritis (MS) and transverse myelitis (inflammation of section of spinal cord, usually 3+ vertebral bodies)
• ON is more severe and can be bilateral (unlike MS)
• Can be relapsing and remitting or monophasic
• No brain lesions